1. Field of the invention
The present invention relates to a display device displaying an image.
2. Description of the Related Art
As the information society develops, display devices for displaying an image are being increasingly required in various forms, and in recent years, various display devices such as Liquid Crystal Displays (LCDs), Plasma Display Panels (PDPs), and Organic Light Emitting Diode (OLED) display devices have been utilized.
The display device includes a display panel, a data driving unit and a gate driving unit. The display panel includes data lines and gate lines, and pixels are defined at each point where the data lines and the gate lines intersect. The data driving unit provides data signals to the data lines. The gate driving unit provides scan signals to the gate lines.
A transistor is disposed in each sub-pixel defined in the display panel. Characteristic values of the transistors in each sub-pixel may be changed, or a deviation of the characteristic values of the transistors in each sub-pixel may be generated. Also, when the display device is the OLED display device, a deviation of a degradation of an OLED in each sub-pixel may be generated. Such a phenomenon may generate a luminance non-uniformity between sub-pixels and may degrade display quality
Thus, in order to resolve the luminance non-uniformity between the sub-pixels, a pixel compensation technique for compensating a characteristic value change or a characteristic value deviation of an element (e.g., a thin film transistor and an OLED) in a circuit is proposed.
The pixel compensation technique is a technique which senses a specific node of a circuit in the sub-pixel, changes data provided to each sub-pixel using a result of the sensing, and thus prevents or reduces the luminance non-uniformity of the sub-pixels.
Although the pixel compensation technique according to the prior art is being provided, a phenomenon in which the luminance compensation of the sub-pixel or the luminance deviation compensation between the sub-pixels is not performed is still generated.